Such exhaust gas cooling modules are known. For the reduction of pollutants, an exhaust gas flow is supplied to an exhaust gas cooler in a controlled manner. In order to reduce interfaces, which in the past have been established through hose or conduit connections between the individual aggregates, modules have been developed that were fastened to each other in a flow-conducting manner via simple flange connections. For example, the housing of an exhaust gas recirculation valve is directly connected with a heat exchanger. If applicable, bypass channels and bypass flaps were also integrated.
Such a module is described, for example, in WO 2009/047278 A1 wherein an exhaust gas cooler, an exhaust gas recirculation valve, a bypass flap with an actuator, as well as a vacuum container and a thermostat valve are fastened to a support element without requiring additional connection lines.
A cooling module is described in DE 10 2006 033 313 A1, wherein a non-return valve with two non-return flaps is arranged downstream of an exhaust gas heat exchanger that can be bypassed via a bypass channel, whereby a return flow of exhaust gas from the bypass channel into the cooling channel, and vice versa, is prevented.
The aforementioned exhaust gas recirculation systems are, however, only partially suitable for use in commercial vehicles that usually have an exhaust gas manifold with two separate exhaust gas flow passages which are often combined in the region of the exhaust gas recirculation at least in the region of the cooler. This leads to a substantial reduction in existing pressure pulsations. Since supercharged engines are additionally often used so that a high counter-pressure prevails in the region of exhaust gas introduction into the distribution rail, the pressure gradient is often insufficient to reliably provide a sufficient quantity of recirculated exhaust gas.